Length control apparatus



Nbv; 18, 1952 R, MANSELL 2,618,046

LENGTH CONTROL APPARATUS Filed D80. 9, 1947 2 s l'lEETs sl-fEET lINVENTOR. LELAND R. MANJELL.

ATTORNEY.

Nov. 18, 1952 L. R. YMANSELL 2,618,046

LENGTH CONTROL APPARATUS Filed Dec. 9, 1947 2 SI'IEETS-Sl'lEET 2INVENTOR. LELA N 0 4 R MANSELL ATTORNEY.

Patented Nov. 18, 1952 UNITED STATES PATENT OFFICE 13 Claims.

1 This invention .is1directed: to; the: provision .of apparatus forinsuringcutting moving stock such asapipe, tubing, rodsand the like intopieces of substantially predetermined? length as the stock iscontinuously generated in.a; continuous mill or other. apparatus, the;invention also including further objects'and novel featuresl'of design,construction and arrangement as will hereinafter more fully appear.

As it is particularly adapted for use in connection with the severingof'vbutt weld pipe after its formation in a: continuous buttweldmill.Ivshallvdescribe the invention more, especially when utilized for,that-purposebut not-by way of limitation .orrestrictionthereto as itmay be employed advantageously; for many other purposes and inconnection with other kinds of stock if desired; It will moreover beunderstoodthatthe term;pipe is herein used in .a' generic sense toindicate. any elongated generally; like material such as rods ortubesaswell as the class of-goods specifically known as pipe:

Buttweld pipe as produced-ma continuous mill is; delivered from the-.latter vath-igh speed.

and is. usually cut into approximate lengths at a point relativelyclose-to that of its exit'from themill by someappropriatem'echanism suchas the flying saw disclosedin U.- S.- Patent 1,946,926, granted:Eebruary 13., 1934 to -J. Barton' to which reference may 'be had for adetaileddescription-of the saw zanditsaotuating mechanismiSpeakinggenerally, however,- such a saw is, positioned adj acent the-line-;of travel .oflthe' pipe upon..a.-table. movable parallel theretoand.

electricallyvcontrolled means are provided -for moving. it from a.position otrest until it attame-approximately the speed or the pipe-atwhich time the saw is forced .against'the latter to sever it, afterwhich the table is brought to rest and then returned to its firstposition preparatory to, being again actuated to cut off-thesucceeding-length of pipe.- The motion of the tableis initiated by aswitch controllingthe-circuit whichenergizes a magnetic-clutch operativewhenengaged to causethesaw table to be activated from the main drive.mech'anismlof the mill, and. theoretically, such switch could .betset toclose the circuit at predetermined fixedtime intervals as at constant:pipe ,speedthis would necessarily result in the pipe being cut intoapluralityof sections of the desired .le'ngthof,,say, 20 feet. Inpractice, however, unavoidable variations inoperating conditionsmateriallyaffect the length of the pieces consecutively cut in thismanner so that desirable low length tolerances cannot "with anycertainty be obtained with a given setting of the switch interval. Thus,for

example, slight changes in the speed' of ithe mill, in thetemperaturefof'the furna'ceiin whichthe' skelp is heated, or in thethicknessof the skelp itself, either. alone or in combination, changethe velocity at which the pipe emergesirom the mill and a saw activatedat fixed intervals of time would therefore cut the pipe'into longersections whenthe velocity of thepipe' is high and shorter ones whenit'is' low. As disclosed in said patent, however; a flag switch may beemployed for controlling the saw activating cir-- cuit but as thetimexlag between actuatiomofthe flag switch byv the leadin'ggend ofthepipe and 1 the operation'of the'sawupon it is constant, resetting ofthe position of the flag-switch is required from time to time in aneffort to effect the requisitecompensation; But such resetting." ifand'when made, is necessarily in accordance with the judgment ofthe:operator and it results that out of, say 10,000 pieces of pipe,many'are too short and others to lon because followin a change inoperatingconditions-either the-flag switch was not properlyreadjusted'or was-not readjusted at all.

In the control-system disclosed'and'claim'ed in U. S; Patent.2,395,562,granted'to me Febru-' ary 26, 1946, I provide means whereby. theilagswitch controlling ;the' operation of the saw is" automatically shiftedlongitudinally; of i the pipe' in one directon or the other tocompensate "for changes in operating conditions-thereby insur ing;that aseries of the-severed pipes will besub stantiall-yj of the same lengthirrespective of such changes,- said :means being further automaticallyoperative :to properly adjust the position of the flag switchwhen'ithe-length of the sections of but one. Systems using but one-suchswitch,-

however, as pointedv out in my said Patent- 2,395,562, heretofore havebeen incapable of producing substantial uniformity in the length of thepieces of pipe as they are cut, and the present invention is thereforedirected to the provision of length control apparatus in which but onefla switch is employed but which is effective to com- 3 pensateaccurately for changing conditions and therefore to bring about accuratecutting to substantially any predetermined uniform length of any numberof pieces or pipe sections from a continuous length of pipe as it issuesfrom the mill. In its elimination of a second flag switch and in otherrespects it therefore consitutes an improvement on my said priorinvention and is of especial utility in mills in which the pipe or otherarticle to be severed into lengths is generated at very high speed.

In the accompanying drawings, to which reference may now be had,

Fig. l is a substantially diagrammatic plan view of a portion of acontinuous butt weld pipe mill and flying saw assembly of conventionaldesign in which apparatus embodying the invention is incorporated;

Fig. 2 is an enlarged diagrammatic representation of certain of thecontrols incorporated in said apparatus;

Fig. 3 is a further enlarged end elevation of one of the switchesutilized; and

Fig. 4 is a schematic diagram of the electrical control systempreferably employed.

To facilitate a proper understanding of the invention I shall firstdescribe certain mechanical details thereof as shown in Figs. 1-3inclusive and then the preferred electrical circuits and connectionsschematically illustrated in Fig. 4. Thus in Fig. l M designatesgenerally a continuous butt weld pipe mill of any suitable constructionwhich may be driven by a motor i which also, through the medium of abelt 2, supplies power for actuating the sliding table 3 on which themotor driven circular flying saw 4 is mounted. This table is arrangedfor reciprocation parallel to the path of the pipe on a base 5 throughthe medium of a crank i3 and pitman 'l', the shaft 8 on which the crankis mounted being controlled by an electrically actuated clutch 9 bywhich it can be connected and disconnected through reduction gearing tomotor I. The pipe as it emerges from the mill moves past the saw to aconveyor IU of suitable construction for carrying it in a direction awayfrom the mill for ultimate reception on a cooling table or some otherapparatus (not shown), and thus when the clutch is engaged, with table 3at that end of its travel nearest the mill, the table will be drawn withincreasing speed in the direction in which the pipe travels along thepath P, designated in dot and dash line, until it attains approximatelythe speed of the pipe at which time the saw is caused to movetransversely so as to sever it and is then retracted as the table comesto rest at the opposite end of its stroke from which point the table isreturned during the next half revolutionof shaft 8 to initial positionpreparatory to cutting oif the next piece of pipe.

The operation of the magnetic clutch and hence the activation of the sawtable is controlled by a continuously operating drum limit switch IS insuch manner as to cause the clutch to engage at properly timed intervalsfor cutting the pipe to the desired length and it is disengaged bysuitable means (not shown) when the table has been restored to startingposition each time after the pipe has been cut, the details of operationof the saw and table upon engagement of the clutch being more fullyexplained in said Patent 1,946,926, which illustrates one of many knownarrangements for coordinating the action of these units.

In accordance with the present invention,

which is thus primarily directed to automatically controlling theinterval between successive engagements of the clutch to compensate forchanges in the rate of speed at which the pipe issues from the mill,instead of employing a flag switch to be engaged by the pipe end toenergize the clutch operating mechanism, the contacts of thecontinuously operating drum switch l5 are connected with the clutchcontrol circuits so as to cause the clutch to engage at a predeterminedangular position of the switch drum during each revolution of thelatter. As many kinds of known motor driven drum switches are capable ofperforming this function the specific details of switch l5 are notillustrated and form no part of the invention which is concerned moredirectly with control of the speed at which the switch operates ineffecting the desired coordination between its rotation and the speed ofthe pipe issuing from the mill.

The drum switch may be driven by a shaft l6 from a variable speedreducer I! in turn driven by belt I8 from another speed reducer [9connected with the shaft of a variable speed motor 20 the speed of whichis controlled by a rheostat 2! in its energizing circuit. This rheostatis connected with and operated by a compound-wound reversible directcurrent motor 25 which when energized thus adjusts rheostat 2! to causean increase or decrease in the speed of motor 20, depending on thedirection of rotation of motor 25. While in practice it is preferable tointerpose speed reducing connections between the shaft of the latter andthe variable contact of rheostat 2 l, showing of such connections hasbeen omitted from the'drawing as their functions are well understood andtheir specific structure forms no part of the invention. They should,however. insure substantially immediate response in changing theeffective resistance of rheostat 2! whenever motor 25 is energized andthe extent of such change and hence of the resultant change in the speedof motor 28 should always be directly proportional to the time duringwhich motor 25 is in operation and correspond in direction to that ofrotation of the motor shaft. Thus while switch motor 2i! operatescontinuously and always in the same direction when the mill as a wholeis in operation and causes clutch 9 to become engaged at intervals thetiming of which, through drum switch [5, depends on the speed of motor20, the speed controlling motor 25 functions only intermittently and mayoperate in either direction depending on the nature of the changerequired in the speed of motor 28 to compensate for a change in the rateof production of pipe by the mill, to which rate the energization anddirection of motor 25 are directly correlated by means now to bedescribed.

These means comprise a single flag switch 30 interposed in the path ofthe pipe and as indicated in Fig. 1 adapted to be engaged by thesuccessive leading ends of the pipes as they move along conveyor Ill,the flag switch completing a circuit through its contacts while it isengaged and opening it automatically as each cut-off section of the pipemoves beyond the switch and before the succeeding pipe end has reachedit. It is of course understood that conveyor IQ includes means forcarrying the pipe sections, after they have been severed :by the saw,away from the mill at a rate faster than that at which the pipe issuesfrom the mill so the trailing end of one pipe section reaches and passesbeyond flag switch appreciably before the leading end of the :zzaeasgoac.1'succeedingssectionfreachesdt:andqnormally-before s51 the'-:latter:section: has been severed by. the' saw. The flag: switch isadjustable along conveyor: 1| :1; since: its-position directly..determinesthelen'gth of the pipe sections cut by-thesaw'z'when. it ismoved toward or. awayfrom the saw-and mill: and "then clamped =in-fixedposition shorter or. longer seetions are thereafter produced.

Correlated with the circuit controlledby -fiag figure.

These. circuitsare" energized;conveniently at 250v; D...C from: mainfeed lines L, L';=under:the control of: angoperators switch: '4 Iwhich-senergizes a i relay 7; '42 through; :lead 43', when line switches44, motorswitches tandzoperators .switch 4 i are closed. .If-now it-beassumed that fiagswitch'efl :is'set at a-nxedposition.alongcon- -veyor--5| 0 corresponding 'to' the desired ':length* of the pipe sectionstobe=cutithatcam-3 2' is adjustedso it closes cam-switch 3 Isimultaneously-with thewclosingofrflag switclr-3li whenlthe latter has'b'eenclosed by a section of pipe 'cut or *beingcut ,to exactly thedesired length and that. motor '20 is 1 operating. at. precisely therequisite speed, to

bring=thelsaw into play attheaproperintervalsJior cutting the pipesections to that lengthwe attain i that I term-the ideal condition underwhich ..no changein that speedcis required. and motor shouldthereforeremahi-deenergized.

.. Now w-henofiag. switch 35 andzcamswitch-i 3 l are open I(Fig..l.4).relays 5!, .52. respectivelya.-in- :Jcircuitv with them. are. deenergizedandmo =eiiec- ..tive current flows throughtheir contacts 5l', 5 l '(5252 andf'w-hen. the switches close slmultaneously the-same .condition..obtains= .save

that the relays'are energizedand their contacts .1 shifted. Whencamswitch 3! thereafter. opens, switch keeps relay 5| energized'throughahead 1' 50.;and contacts 51"}"523 butno' otherl effect ;is roduced. andcam :32 is therefore designedilto open-switch 3! appreciablybeforethei'tr'ailingend .of a severed pipe section 'can 'pass flagswitch 30. "The contacts of'rel'ays 51,". 52 are so connected. however;that. when either of these .r eIaysI alone is energized the arm'atureofmotor 25'-is-."also energized in one direction orthe other depending onwhich'relay. is'so energized.

Now whenthe" millfdelivers' the, pipe at antincreased-or decreased ratedue; to. some change inoperating conditions; a s'when for exampleh'ot- 1teror colder skelp issupplied, the timing of the closing of'the-flag'switchj is modified accordingly 35TH? thencloses either"before. or afterbutnot simultaneously withhcam' switch"3land'fthejcircults controlled'byth'ese two switches aresoidesigned thatwhen this occurs speed'control motor 25' isenergized' in the" directionappropriateto change" the" setting of rheo'stat' 2 LV and .therebyeither decreas'e'or increase the speed of m'otoiZfl j and hence drumswitch .I 5 to lengthen-orshorten :the interval -between" successiveengagements of clutch 9.

More specifically a relay53 provided withnor- 1ay53 is actuated toclosesaid contacts and cur- .-"of:" the invention include a delayed actionrelay whose single normally'clo'sedcontact 66' forms apartv of thecircuit 2' energizing shorteri rclayf fi when flag switch*30fcloses'before Icam 'sw -it'ch 31 i' the sole" function-*ofthisrelay:- 66. .is to prevent establishment of a circuit throughsho'rterirelay "if for anyreasonifiag switch- 36 should remainzclosedafter'onepipe section has passed-it before .the succeeding-onehasreached it and after-cam '--"switch I 3 l has opened. Iv This Icondition 15 arises 'irarely, ifat 'allgand relay BB is therefore'a meresafety device -to avoid the'e'ffects of possibleimproperoperationof'fiag switch 30.

rent then flows through motor 25 and its series 1 field 59: in-thedirection to move rheostat 2l 'for decreasing the? speed of motor- 20.v. 'Ihis' relay 53 may-therefore-be referred' toas the longer .-:relaysince the effect of decreasing the speed of motor-20 isto prolong thetime interval between successive engagements of clutch 9 and thuspermita greater length ofpipe to passfromthe'mill :between successivecuts, inother words; to cause asection of pipe longer than the preceding-one to:be severedby the saw on its next 'and'succeed- .ingjcycles ofoperation.

-When the =fiag switch later closes as 2; result of contact of the endof a pipe section with it.

-relay-52-is? energized toshift contacts-52', 52" -and therebydeenergize -relay- 53- which consequently "interrupts the circuitenergizing motor .25; motor 20 thereaftercontinuestooperateat itsnewspeed; corresponding 1 to the new setting vofrheostat '2 I until thelatter is again shifted.

;Motor. 25 is .preferably'a' constantspeed-one although subject .tomanual'control by a rheostat 62in series with'its shunt field 63whichtis always energized throughswitches 45'when the 'system isoperating,- and itwill'be apparentthe i extent tow hich motor 25 variesthe setting'of rheostat 2| and hence the-speed of'motor :20--'is Arelated tothe extent of. departure 'fromthe Drop- 30 er-length of thepipe section-being cut since this factor directly controlsthe timeinterval between the operation of-cam' switch 3i and flag switchfifithere being of'xcou'rse no such interval 1 when the section is exactly:the .proper'length as these two switches then 'close' simultaneously.

When the, pipesectionsevered *by. the: saw is longer than it shouldbeflaswitch'30 closes bei fore cam'switch 31 {thereby energizing a'. shorterrelay 65, which thereupon ,closes'its contacts 65,- 65".:to energizemotor 25 with opposite polarity' and so vdrive it in the reverse.direction from that in whichitisdrivenwhenthe-longer relay :53 isenergized; as is obvious from Fig: 4 thepo- *larityof theterminals ofseries'fi'eld 59. 'andishunt i field 63. remains always the same while"that of mthe 'motorarmature is reversible; "dependings'on whether it isenergized through the; contacts of :Jon'ger relay '53 orrshorter relay65.

Other instrumentalities indicated in Fig-fidesir'ably provided but notessentialto the practice -Manualswitches-"Ill, H, conveniently 'of'theof motor 2B'by opera'tingm'otor' 25in one direc- "The' switchesusuallyhre emcommodate the apparatus to a shift in the-position or flagswitched such asoccurswhen-itis J desired to produce, ior-exa1nple,--3G'sections.- after the apparatus has been previously set to cut 20' ones.

Referring now more directly to the effects of the functioning of thevarious instrumentalities and circuits heretofore described, it will beassumed the mill is beginning operation and it is desired to producepipe sections of a predetermined length, say 20', after the pipe isissuing from the mill at its normal speed, for example 600' per minute.The operator first closes line switches 44, 45 and 4| to energize thesystem and start motor 20, then by manipulation of push button switches10, H he can set rheostat 2! to a position corresponding to theestimated proper speed for motor 20, flag switch 30 being set along theconveyor at exactly 20' from the point at which the saw under normalconditions first attacks the pipe and cam switch 31 adjusted to closejust as this contact is made. Thereafter upon each revolution of drumswitch I5 driven by motor the drum switch contacts l5 close and clutch 9is engaged to rotate shaft 8 through one complete revolution and thuscarry the saw through one cycle of its operation, each cycle ending withthe saw retracted and the table at rest at the right hand end of itspath as in Fig. 1. As soon as the clutch is engaged the saw tablecarrying the rotating saw starts to move toward the left in Fig. 1 andvery soon thereafter as the table attains the speed of the pipe the sawmoves in toward the pipe path and attacks the pipe. At this momentswitch 3| is closed by cam 32 and if rheostat 21 has been properly setso the speed of motor 20 corresponds exactly to the speed of issuance ofthe pipe from the mill, the leading and of the pipe engages and closesflag switch 30 simultaneously with the closing of switch 3! and thearmature and series field of motor remain deenergized.

If, however, rheostat 21 has been set to drive motor 20 too fast, soclutch 9 is engaged to bring the saw into contact with the pipe at apoint 'less than 20' from its end, cam 32 causes switch 3! to closebefore the pipe end can reach and close flag switch 39. As beforeexplained, upon the closing of cam switch 3| before flag switch closesmotor 25 is energized to adjust the rheostat to slow down the operationof drum switch !5, and although the section immediately bein cut is thenshorter than 20 the adjustment of the rheostat insures that thesucceeding one will be longer; if flag switch 30 closes almostimmediately after cam switch M, as is the case when the section beingcut is nearly as long as it should be, motor 25 operates only for ashort time, for of course only a small adjustment of rheostat 2| isrequired. If this interval is longer,

7 however, motor 25 operates for a greater period and thus makes alarger adjustment of the rheostat so as to cause a correspondinglylonger section to be cut on the succeeding cycle, but the speeds of thevarious instrumentalities are desirably proportioned so that motor 25cannot normally over-compensate for a single persistent it is attainedswitches 30, 3i close simultaneously,

motor 25 remains deenergized, and motor 20 thereafter continues tooperate at constant speed until the pipe speed again changes, therebynecessitating further compensation.

Conversely, whenever the speed of the pipe becomes greater than that towhich the then speed of drum switch l5 corresponds a pipe section isproduced that is too long; flag switch 39 therefore closes before camswitch 3| and motor 25 thereupon operates in the proper direction toincrease the speed of the drum switch and bring the system again intosynchronism to produce sections of the desired length substantially inthe same way as when the sections are too short, the functions of theshorter relay and of cam switch 3| in interrupting its effect at theappropriate instant being apparent from what has heretofore been said.

It will of course be understood that once the ideal conditions have beenattained, theoretically no further action on the part of the systemshould be required, at least until sections of another length are to becut or a change in the mill speed is designedly made. As has beensuggested, however, many unforeseeable factors not under the control ofthe operator can and often do affect the speed at which the pipe isdelivered by the forming mechanism of the mill, as for example changesin the thickness or temperature of the skelp delivered to the latter oreven spontaneously occurring changes in the condition of the millitself, and it is in compensating for their effects that the presentinvention finds its primary usefulness. 1

I have herein more particularly referred to use of my system incontrolling the length of pipe sections out by a flying saw carried by asaw table arranged to travel periodically along 2. rectilinear path andto return along the same path to starting position after a out has beenmade,

but it will be apparent the system may be equally well employed inassociation with saw carrying mechanism partaking of oscillatory orpendulumlike motion in opposite directions, or periodic motion ofrevolution along a closed path about a center. saw table consequentlyareintended to include such other motions as well, saws of the pendulumand the rotating or turntable type being familiar to the industry, andthe employment of my system for controlling their operation willtherefore be obvious from what already has been said.

Moreover it will be apparent that to sever the pipe a relative motionbetween it and the saw is all that is required and consequently the pipemay equally well be moved against the rotating saw transversely of itsown path, as by a movable section in the runout table, the action ofcourse being correlated with the movement of the saw supportingmechanism in substantially the same manner as when the saw is movedtoward the pipe, and since mechanisms adapted for this purpose are wellknown in the art they require no description or illustration as theirspecific construction forms no part of the invention.

While I have herein described one embodiment of my invention which iswell adapted for attainment of the object of the latter, I do notthereby desire or intend to restrict or confine myself specificallythereto as many changes can be made in the design, construction andarrangement of the mechanical and electrical instrumen- Terms suggestingreciprocation ofthetalitiesemployed and in the circuits by which the'latter are controlled I and actuated without I departing from the spiritand scope of the in-' vention as defined in the appended claims.

Having thus described my invention, I claim.-

and desire to 1 protect by Letters Patent'of the United States:

l.-A control system'fora flying saw assembly adaptedto cut intosections'an elongated object I traveling along a rectilinear pathincluding means for reciprocating the saw in directions generally 1parallel to said path, comprising"continuously operating switch'meansfor intermittently actuat ing said reciprocating means'andmeanscontrolling the speed-ofsaid continuously operating" switch meansto thereby "control the'frequency'or the movements of the saw incorrespondence to therate of movement-oi the object.

2. A control systemfor a flyin saw assembly adapted to cut. intosections an elongated object traveling along a rectilinear pathincluding means for reciprocating the saw indirectionsgenerally;parallel to said. path, comprising continuously j operating switch meansfor intermittently actuating said reciprocating means, means controllingthe speed of said continuously operating switchv means to therebycontrol the frequency or" the movements of the saw incorrespondence tothe 3. A control system for a flying saw assembly.

adapted to cut into sections an elongated object traveling along arecilinear path including means for. reciprocating the saw in directionsgenerally parallel to said path, comprising continuously operating.switch means for controlling said means, and means adapted to beactuated bysuccessive leading ends of the object after they are formedby the saw for controlling the speed of said continuously operatingswitch means.

4. A control system for a flying saw assembly adapted to cut intosections an elongated object traveling along a rectilinear pathincluding means for reciprocating the saw in directions generallyparallel to said path, comprising continuously operating means forintermittently actuating said reciprocating means, means controllin thespeed of said continuously operating means to thereby control thefrequency of the movements of the saw in correspondence to the rate ofmovement of the object, a switch disposed in said path adapted foractuation by successive leading ends of the object after severance bythe saw, and another switch actuated by said saw reciprocating means,said switches being respectively oppositely individually operative tochange the speed of said continuously operating means and adapted whenactuated simultaneously to maintain said speed substantially constant.

5. In a control system for a flying saw assembly adapted to cut intosections an elongated object traveling along a rectilinear pathincluding mechanical means for activating the saw to move it along thepath substantially at the speed of the object, transversely into saidpath and to then return it to starting position, and electricallycontrolled means for intermittently actuating said mechanical means, acontinuously operated switch adapted to periodically successively closeand open a circuit including said electrically controlled means, avariable speed motor for driving said switch, meansfor controlling thespeed of said motor, a reversible motor operative to ac tuate'said'speedcontrollin means, a switch mechanically interconnected with said sawactivating means controlling the reversible motor circuitto drivethe-reversible motor in one direction; a flag switch positioned forengagement by the object controlling the reversible motor circuit todrive the reversible motor in the opposite di-' rection, and meansinterposed in said circuits operative to maintainthereversible motordeen-' ergized when said last mentioned switches are ac:

tuated simultaneously.

6. Apparatusfor controlling an intermittentlyactivated flying sawadapted to cut into succes sive sections a continuously generatedelongated object, comprising means including a mechanically actuatedswitch for intermittently activating the saw,- a variable speed motorfor driving said switch, and means controlling the speed-of saidmotorincludinga rheostat in the motor energiz ing circuit, a reversiblemotor foroperating the directions,

rheostat selectively in opposite switches controlling the reversiblemotor energizing circuits for energizing said motor"respec'- tively'inopposite directions, means controlled by each switch for-deenergizingthe reversible motorcircuit controlled by the other'switch, and

means respectively actuated bythe saw activating means and bythesuccessive leading ends of the object for operating said last mentionedswitches whereby-either reversible motor energizing-circuit whencompleted upon the closing of its controlling switch is interrupted uponsub:- sequent closing of the other switch.

7. In a control system for a flying saw assembly adapted to cut sectionsconsecutively from a continuously generated elongated object includin aswitch operative to cause'the saw to performa cutting cycle;continuously operating means for periodically closing and opening theswitch, means for controlling the speed of said continuously" operatingmeans and switches respectively actuated by the saw activating means andby the successive leading ends of the object independently operative toenergize said speed controlling means respectively in oppositedirections, each of said last mentioned switches being operative whenactuated after actuation of the other to interrupt the speed controllingmeans energizing circuit theretofore completed by said other switch.

8. In a control system for a flying saw assembly adapted to cut sectionsconsecutively from a continuously generated elongated object including aswitch operative to cause the saw to perform a cutting cycle,continuously operating means for periodically closing and opening theswitch, means for controlling the speed of said continuously operatingmeans, switches respectively actuated by the saw activating means and bythe successive leading ends of the object in dependently operative toenergize said speed controlling means respectively in oppositedirections, and means for maintaining said speed controlling meansinactive when said switches are actuated simultaneously.

9. In flying saw activating mechanism control means, a switch operativeto intermittently close and open a circuit, variable speed means foractuating the switch continuously, means for controlling the speed ofsaid switch actuating means, and means responsive respectively to theposition of the saw and the position of the object being cut therebyindependently operative to change said speed in opposite directions andsimultaneously operative mutually to neutralize each other against suchchange.

10. In control system for a flying saw assembly adapted to cutconsecutive sections from a continuously generated elongated movingobject and including a reciprocable saw table, a saw, and means operableto reciprocate the table, continuously rotating means adapted to actuatesaid last mentioned means periodically whereby to cause the saw to severthe object into sections of substantially equal length when the objectis being generated at a predetermined speed, and means automaticallyoperative to change the rate of rotation of the continuously rotatingmeans in correspondence with changes in the rate or generation of theobject to thereby vary the timing of attack of the saw upon the latter.

11. In a control system for a flying saw assembly adapted to cutconsecutive sections from a continuously generated elongated movingobject and including a reciprocable saw table, a saw, and means operableto reciprocate the table, continuously rotating means adapted to actuatesaid last mentioned means periodically whereby to cause the saw to severthe object into sections of substantially equal length When the objectis being generated at a predetermined speed, and electrically actuatedmeans including a switch actuated by the front end of the objectoperative to automatically increase the rate of rotation of thecontinuously rotating means upon an increase in the rate of generationof the object and thereby accelerate the period of each cutting cycleand the timing of attack of the saw upon the object.

12. In a control system for a flying saw assembly adapted to outconsecutive sections from a continuously generated elongated movingobject and including a reciprocable saw table, a saw, and means operableto reciprocate the table, continuously rotating control means adapted toactuate said last mentioned means periodically whereby to cause the sawto sever the object into sections of substantially equal length when theobject is being generated at a predetermined speed, and means includinga switch mechanically actuated from said table reciprocating meansoperative to automatically decrease the rate of rotation of the controlmeans upon a decrease in the rate of generation of the object andthereby decelerate the period of each cutting cycle and the timing ofattack of the saw upon the object.

13. In a control system for a flying saw assembly adapted to cutconsecutive sections from a continuously generated elongated movingobject and including a reciprocable saw table, a saw, and means operableto reciprocate the table, a variable speed motor, a switch continuouslydriven thereby adapted to control the timing of attack of the saw uponthe object to sever it into sections of substantially equal length whenit is being generated at constant speed, and means operative toautomatically change the speed of the motor to alter the time of attackof the saw upon the object upon a change in its speed of generation andthereby maintain the length of sections cut subsequently to said changein speed of generation substantially equal to those out prior thereto.

LELAND R. MANSELL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,862,354 Winne June '7, 19321,946,926 Barton Feb. 13, 1934 2,079,974 Trant May 11, 1937 2,211,362Bennett Aug. 13, 1940 2,341,870 Johnston Feb. 15, 1944 2,395,562 MansellFeb. 26, 1946

